Screws are well known fastening means and are fasteners with elongated threaded shanks and a head thereon. The head is shaped so that it may be engaged so that the screw is rotated. The head may have external engagement surfaces such as a hexagonal or a square crown to be engaged by an appropriately socketed driver. The screw head may have interior surfaces thereon to be engaged by a male driver. These surfaces may be a slot, a Phillips recess, a square recess, a hexagonal recess, or other internal driving surfaces These surfaces are engaged by corresponding surfaces on the screwdriver so that the screw is rotated by the driver. In some cases, the screw must be thrust axially along its rotational axis toward the substrate material into which it is being fastened in order to provide for screw thread engagement in the substrate material. This axial force is more often required in inserting wood screws and sheet metal screws, as compared to machine screws.
There have been many kinds of screw-holding screwdrivers on the market, and despite the problems, only minor improvements have been made over the years. The present screw-holding screwdrivers available on the market have many deficiencies, and these deficiencies make them impractical when trying to start a screw into a substrate. Without firmly holding the screw, the screwdriver may cause injury to the user because the bit comes out of the screw and punches the adjacent finger of the user. Such is the result of not firmly holding the screw in place. After such injury, it is clear that an advance in the art was required.
One difficulty in driving a screw into a wood panel or like substrate is getting the point to start into the substrate. It is particularly difficult to initiate engagement of the screw into the substrate on the correct axis without tilting the screw away from the desired line of insertion. This can be mitigated in several ways. One way is by drilling a pilot hole in the substrate. The drilling of pilot holes raises another question because another tool must be brought to the job. In cases of low volume screw insertion, such as the occasional need of a homeowner to insert a screw, the purchase or bringing to the site the drill to create the pilot hole is not justified.
Another way the difficulties in driving a screw can be mitigated is to employ a screw-holding device. Most of the prior art includes a pair of resilient fingers on the screwdriver shank positioned to grasp the screw beneath the head. The fingers are carried on a sleeve which slides on the screwdriver shank and is frictionally retained in position. Such are difficult to use and are not strong enough to apply the considerable axial force necessary to start a screw into the substrate. It is a device which positions the screw, but does not firmly hold the screw while axial force is being applied.